1. Squeeze juice of 1 lime over fish. Combine cornmeal and next 6 ingredients in a large zip-top plastic freezer bag. Pat fish dry with paper towels, and place in bag, shaking to coat.
2. Pour oil to a depth of 1 1/2 inches in a large deep skillet; heat to 325°. Fry catfish, in batches, in hot oil 2 to 3 minutes or until crispy and golden brown. Drain on paper towels.
3. Place catfish in warmed tortillas; top evenly with cabbage, desired amount of salad dressing, salsa, and toppings. Cut remaining 2 limes into wedges, and serve with tacos.